Automatic locking device for chairs



N0. 6I4,-I92. Patented Nov. l5, I898.

' II. W. WELLES.

AUTOMATIC LOCKING DEVICE FOR CHAIRS.

(Appfication filed. Sept. 22, 1897.)

( N 0 Model.)

UNITED STATES PATENT OFFICE.

HOWARD W. WELLES, OF POUGHKEEPSIE, NEW YORK.

AUTOMATIC LOCKING DEVICE FOR CHAIRS.

SPECIFICATION forming part of Letters Patent No. 614,192, dated November15, 1898. Application filed September 22,1897. Serial No. 652,528. (Nomodel.)

To (1% whom it may concern:

Be it known that I, HOWARD W. WELLES, a citizen of the United States,residing at Poughkeepsie, in the county of Dutchess and State of NewYork, have invented certain new and useful Improvements in AutomaticLocking Devices for Chairs, &c.; and I do hereby declare the followingto be a full, clear, and exact description of the invention,such as willenable others skilled in the art to which it appertains to make and usethe same.

My invention relates to a novel form of music-stool, office-chair, orthe like; and the object is to provide a simple, inexpensive, andeffective means whereby the seat may be raised or lowered in a simpleand convenient manner.

To this end the invention consists in the construction, combination, andarrangement of the device, as will be hereinafter more fully described,and particularly pointed out in the claim. I

In the accompanying drawings the same reference characters indicate thesame parts of the invention.

Figure 1 is a vertical section of a pianostool embodying my invention.Fig. 2 is a side elevation of the socket or hub. Fig. 3 is a top planview of the same with the parallel ribs shown in dotted lines. Fig. 4 isa transverse section of the vertically-adjustable cylindrical rod on theline44 of Fig. 1. Fig. 5 is a plan view of the limit or check plate.Fig. 6 is another form of the rod, and Fig. 7 is a perspective view ofthe locking-roller usedin connection with the form of rod shown in Fig.6.

1 represents the seat, which is provided with a bearing 2 to receive theupper end of the cylindrical rod 3, on which the seat freely rotates.This end of the rod is provided with an annular groove 4, the upper wallof which is formed with a series of notches 5, and 6 represents athumb-screw mounted in the bearing 2 and arranged to project into theannular groove 4 to retain the seat in place and at the same time notinterfere with its free rotation on the rod. When, however, it

becomes necessary to raise or lower the rod for the purpose to behereinafter explained, 'the seat is turned to the right or left andraised at the same time, so that the projecting end of the thumb-screw 6will engage one of the notches'5, which looks the seat to the rod toturn therewith. This rod 3 snugly fits the vertical orifice 4 in the hubor socket 8 in such a manner as to admit of a free rotary and verticalmovement therein. The perimeter of the rod is provided with alongitudinal series of alined recesses. 9 9, a single recess 10,arranged at a right angle to and in the same horizontal plane with theuppermost one of the recesses 9, and a longitudinal keyway 12. The hubor socket 8 is provided with a pocket 13, communicating with the orifice4, and the lower wall of said pocket is formed with an inclined face 14,the upper end ofwhich terminates in a shoulder 15. 16

represents a thumb-screw projecting through said hub,with itsinner endextending through the inclined face 14 of the pocket and in the path ofa movable lock or detent in the form rod 3, and it is also provided witha radial teat 20, which projects into said orifice and engages thekeyway'12 in the rod, which permits the rod to slide vertically throughsaid plate and at the same time causes the rod to rotate the plate whenthe former is rotated on its axis. This plate is provided withoppositely disposed concentric slots 21 21, through which the screws 2222 pass to secure it in place on the socket, and from this constructionit will be understood that when the rod is rotated it carries thiswasher with it, and the slots serve to limit the movement of the washerand rod. When the washer and rod are at one end of their movement, theseries of alined recesses 9 are in line with the ball 17 in the pocket18, and when at the other end of its stroke the single recess 10 isvertically alined with said ball, the use of this recess being to limitthe downward movement of the rod.

The hub or socket is provided with a series of four dovetail flanges 23,into which the upper portions of the legs are fitted or driven, and 24represents a series of countersunk orifices to receive the usualwood-screws to assist in fixing the legs in place.

The operation of the device is as follows:

In its normal position, as represented in Fig. 1, the seat is shownadjusted to its minimum height, the rod being held in this position bythe ball engaging the recess 10. When it is desired to elevate thechair, the seat 1 is turned on the rod until the thumb-screw 6 engagesone of the notches 5, which locks the seat to the rod. The seat and rodare then raised to carry the ball above the shoulder 15 and the seatturned to the right until the plane face of the rod is in line with thepocket, the ball in the meantime being supported by the plane face ofthe rod, holding it against the horizontal face of the shoulder. As soonas the seat has been raised the proper distance the seat and rod areturned to the right to their full limit, which brings the row ofrecesses 9 in line with the ball, which drops into the appropriaterecess and away from the shoulder 15. The seat and rod are then lowereduntil the ball rests on the inclined face of the pocket and in contactwith one of the recesses 9 and the vertical face of the shoulder 15,which efiectuall y locks the rod against any further downward movement,as Well as against anylateral or rotary movement, While the seat ispermitted to freely revolve, as heretofore described. When the seat hasbeen adjusted to a position where it is desirable to retain itfor anindefinite period of time, the set-screw 16 is then brought into play toforce the ball into its recess in the rod, and thus effectually lock therod in the hub against accidental displacement.-

In the form shown in Fig. 6 the recesses 9 10 in the rod aresemicylindrical instead of semicircular, and instead of the ball orsphere 17 a solid cylindrical roller 17, as shown in Fig. 7, isemployed. Otherwise the construction and operation are the same.

While I have for convenience described my invention as applied to amusic-stool, it is of course equally applicable to any form of revolvingor oifice chair, tables, and like articles of furniture, and although Ihave specifically described the construction and relative arrangement ofthe several elements of my invention I do not desire to be confined t0the same, as such changes or modifications may be made as clearly fallwithin the scope of my invention without departing from the spiritthereof.

Having thus described my invention, what I claim as new and useful, anddesire to secure by Letters Patent, is-

The combination with the hub 8, provided with the vertical orifice 4 andthe communieating pocket 13 formed with the inclined face 14, andshoulder 15, of a lock or detentlocated in said pocket, the rod 3,provided with alined recesses, substantially as and for the purpose setforth.

In testimony whereof I affix my signature in presence of two witnesses.

HOWARD IV. WELLES.

Witnesses:

E. M. MEEKS, IRVING ELTING;

